Siemens SIMATIC ET 200iSP Operating Instructions Manual page 242

Digital electronic modules
12.1 Digital electronics module 8 DI NAMUR
Quantity
Channel
Measuring frequency (GATE time)
Resolution frequency
● at a GATE time of 50 ms
● at a GATE time of 200 ms
● at a GATE time of 1 s
Input frequency
● max. line length 20 m
● max. line length 100 m
● max. line length 200 m
Maximum line length for counter and frequency meter is 200 m.
1
applies to NAMUR sensors/ sensors according to DIN 19234 and NAMUR changeover contacts /
2
sensors according to DIN 19234 changeover contacts.
applies to NAMUR sensors/ sensors according to DIN 19234/ single contact with 10 kΩ connected
3
and NAMUR changeover contacts/ sensors according to DIN 19234 changeover contacts/ changeover
contacts with 10 kΩ connected.
Input has a switching hysteresis of 0.2 mA (as of product version 05 of 8 DI NAMUR).
4
If the input frequency rises above 8 kHz, correct actual values can no longer be output.
5
Diagnosis for changeover contact sensor types
When a diagnosis is made for the changeover contact sensor type, the digital electronic module
controls the switchover between two input channels. If there is no signal change in the normally
closed contact after the set switchover time (see technical specifications), the module reports
diagnostic information.
Purpose
You can use the diagnosis for
● checking the sensor
● to make absolutely sure that there has been a switchover between a normally open contact
and normally closed contact.
Principle
If the digital inputs of a channel group are assigned parameters as changeover contacts, the
module runs diagnostics for changeover contact sensor types for this channel group. The
tolerated switchover time between the two channels is set to the fixed value of 300 ms.
If the validity check is negative, the following applies:
● The module designates the value status of the normally open contact channel as invalid.
● The module creates a diagnostic entry for the NO contact channel.
● The module triggers a diagnostic interrupt.
The digital input signal and the value status are only updated for the NO contact channel
(channel 0, 2, 4, 6). In the case of the NC contact channel (channel 1, 3, 5 and 7) the digital
242
Technical specifications
5
2
0, 1
50 ms, 200 ms, 1 s
20 Hz
5 Hz
1 Hz
5 kHz
1 kHz
500 Hz
Operating Instructions, 11/2017, A5E00247483-07
ET 200iSP